* configure.in: Rename file to ...
	* configure.ac: ... this.  Add in AC_PREREQ(2.57)
	* config.h.in: Regenerate.
	* aclocal.m4: Regenerate.
	* Makefile.in: Regenerate.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@75621 138bc75d-0d04-0410-961f-82ee72b054a4